I have emailed the guys at Ay-Up, but perhaps someone here has some wisdom.

The 1/2 Epic battery (containing the clever electronics) is designed to give you high, low and flashing modes depending on how you push the button from off:
- short push>high>short push>low>short push>high>long push>off
- long push>flashing>short push>off

Today I changed from flashing as I crested the climb to high for the descent. At the bottom of the hill I couldn't get flashing back. I seem to be stuck with high and off no matter what I do.

Any thoughts?

Plenty of charge (although I have run it down and am now giving it a full charge)
Button feels and sounds as per before
No 'trauma' to battery (ie dropped, soaked)